Hello everyone,
After setting up a version of Jupyterhub based on Swarm (see here for those interested: Get username with dockerspawner ), I am now working on the question of access to a common home folder:
On the jupyterhub/Swarm platform, Containers are now able to start with a uid that is determined and specific to each user who thus obtains access to their home.
Now, I want to provide access to this same folder for each user from another platform: The Littlest JupyterHub distribution (TLJH).
Both platforms are connected to the same LMS (moodle) via ltiauthenticator (this ensures the users to have the same login on both jupyterhub/swarm and TLJH). I would like that on TLJH, the uids are not assigned by order of arrival, but by a calculation which ensures the same uid on each platform and corresponding to the one owning the home.
So, on jupyterhub/swarm, the assignment of a uid has been defined as follows: 1000 + moodle id = uid (for example, for a moodle id = 1, uid is 1001).
So I’m currently looking to force the assignment of a uid calculated in this way on TLJH.
I suppose it is necessary to add code in jupyterhub_config.py or overload a SystemdSpawner class (I specify that the spawner defined is UserCreatingSpawner in this distribution).
Has anyone a solution or an idea ?
SystemdSpawner uses the UID and GID of Linux system users. So, it is not possible to assign dynamic UID and GID as you would do with the containers. A potential solution can be to create system users upon first login with the Authenticator.
You will need to create a custom Authenticator subclassing LTIAuthenticator and LocalAuthenticator and overload the adduser method to create system users with a consistent UID and GID as you do with other JupyterHub platform. Then, when SystemdSpawner spawns a notebook instance, it will have correct UID and GID as other instance and you should be able to share your common NFS share for both JupyterHub platforms
Thank you for your response mahendrapaipuri,
My development skills do not allow me to achieve this… But while searching, I ended up finding a solution:
In the user.py file, I replaced the line
subprocess.check_call(["useradd", "--create-home", username])
by
moodle_id = str(int(username.replace('jupyter-', ''))+1000)
subprocess.check_call(["useradd", "--create-home", username, "--uid", uid])
It’s not a very elegant solution, but it does the job…
A few more tweaks to the system and I will be able to validate that everything is working properly!
I will add a little note here to confirm…
Solution confirmed!
The two platforms swarm and tljh now allow users to find their home via NFS…